Walnut Creek IA 01-WPS-372
mouth (S18 T83N R2W Jones Co.) to confluence with White Oak Cr. in S19 T83N R3W Jones Co.
- Cycle
- 2016
- Release Status
- Final
- Overall IR
- 5 - Water is impaired or threatened and a TMDL is needed.
- Trend
- Unknown
- Created
- 6/28/2016 4:27:43 PM
- Updated
- 11/30/2016 7:59:59 AM
The presumptive Class A1 (primary contact recreation) uses remain "not assessed" (IR 3a) due to the lack of information upon which to base an assessment. The Class B(WW2) aquatic life uses remain assessed (evaluated) as "partially supported" (IR 5b) due to occurrence of a fish kill in 1999. Due to the absence of kills in the five years following this kill, this assessment segment is considered “evaluated.” Due to EPA uncertainty regarding the full recovery of the aquatic life in this stream subsequent to the kill, this stream segment was placed on Iowa’s 2006 Section 303(d) list where it remains.
The assessment of support of the Class B(WW2) aquatic life uses remains based on the occurrence of a fish kill in 1999. This fish kill occurred on Walnut Creek near Olin in Jones County on July 26, 1999. Approximately three miles of stream were affected; an estimated 120 fish were killed. This kill was attributed to runoff of animal waste from an open (cattle) feedlot. The person reporting the kill had noticed manure in South Fork Walnut Creek a week prior to the kill. Although no source of the animal waste was identified, a waterway containing manure leading from open cattle lots to the South Fork Walnut Creek was found during the investigation.
According to IDNR’s assessment/listing methodology, the occurrence of a single pollutant-caused fish kill, or a fish kill of unknown origin, on a waterbody or waterbody reach during the most recent assessment period indicates a severe stress to the aquatic community and suggests that the aquatic life uses should be assessed as “impaired.” If a cause of the kill is identified, and the cause is either known, or suspected, to be a “pollutant”, the assessment type is considered “monitored” and the affected waterbody is a candidate for Section 303(d) listing. Fish kills attributed to a pollutant, but where a source of the pollutant was not identified and/or where enforcement actions were not taken against the responsible party, will be placed into Integrated Report subcategory 5b. The intent of placing these waterbodies into Category 5 is not to necessarily require a TMDL but to keep the impairment highlighted due to the potential for similar future kills from the unaddressed causes and/or sources. This assessment segment remains in Category 5b of Iowa’s Integrated Report.